If you already have the bones of kegging system, and want to upgrade to a 2 tap tower, this is the unit for you. This system comes with 2 used Corny kegs tested to hold pressure. New replacement O rings come with this kit, along with a double tap tower. Install a draft tower on a counter-top, or convert a chest freezer by adding a double tap draft tower to the top. This system is designed to deliver homebrew from a two USED 5 gallon cornelius kegs through a double tap commercial draft tower "bar" setup.